Magnetoresistance effect element, magnetic head and magnetic reproducing system

ABSTRACT

There is provided a magnetoresistance effect element capable of precisely defining the active region in a CPP type MR element and of effectively suppressing and eliminating the influence of a magnetic field due to current from an electrode, and a magnetic head and magnetic reproducing system using the same. The active region of the MR element is defined by the area of a portion through which a sense current flows. Moreover, the shape of the cross section of a pillar electrode or pillar non-magnetic material for defining the active region of the element is designed to extend along the flow of a magnetic flux so as to efficiently read only a signal from a track directly below the active region. When the magnetic field due to current from the pillar electrode can not be ignored, the magnetic flux from a recording medium asymmetrically enters yokes and the magnetization free layer of the MR element to some extent. In expectation of this, if the cross section of the pillar electrode is designed to be asymmetric so as to extend along the flow of the magnetic flux, the regenerative efficiency is improved.

CROSS REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority fromthe prior Japanese Patent Applications No. 2000-301118, filed on Sep.29, 2000; the entire contents of which are incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to a magnetoresistance effectelement, a magnetic head and a magnetic reproducing system. Morespecifically, the invention relates to a magnetoresistance effectelement for causing a sense current to flow in a direction perpendicularto the plane of the element to detect an external magnetic field, amagnetic head using the same, and a magnetic reproducing system usingthe same.

2. Description of Related Art

Conventionally, the readout of magnetic information recorded in amagnetic recording medium has been carried out by a method forrelatively moving a reproducing magnetic head having a coil with respectto the recording medium to generate an electromagnetic induction todetect a voltage which is induced in the coil by the electromagneticinduction. On the other hand, an electromagnetic effect element (whichwill be hereinafter referred to as an “MR element”) has been developed.The electromagnetic effect element is being used for a magnetic sensor,and mounted on a magnetic head (which will be hereinafter referred to asan MR head) for use in a magnetic reproducing system, such as a harddisk drive.

In recent years, the size of a magnetic recording medium is decreasing,and the capacity thereof is increasing, so that the relative velocity ofa reproducing magnetic head to the magnetic recording medium isdecreasing during the readout of magnetic information. For that reason,it is required to provide an MR head capable of taking out a largeoutput even if the relative velocity is small.

According to such a request, it has been reported that a multilayerfilm, such as Fe/Cr or Fe/Cu, wherein ferromagnetic metal films andmagnetic metal films are alternately stacked on certain conditions,i.e., a so-called “artificial lattice film”, has a giantmagnetoresistance effect (see Phys. Rev. Lett. 61 2474(1988), Phys. Rev.Lett. 64 2304 (1990)). However, since magnetization is saturated in theartificial lattice film, a required magnetic field is high therein, sothat the artificial lattice film is not suitable for the material of afilm for an MR head.

On the other hand, there has been reported an example where a largemagnetoresistance effect was realized even if a ferromagnetic layer isnot antiferromagnetically connected in a multilayer film having asandwich structure of ferromagnetic layer/non-magneticlayer/ferromagnetic layer. That is, a magnetic field due to exchangebias is applied to one of two ferromagnetic layers, which sandwich anon-magnetic layer therebetween, to fix magnetization, and themagnetization of the other ferromagnetic layer is inverted by anexternal magnetic field (a magnetic field due to signal or the like).Thus, by changing the relative angle between the magnetizing directionsof the two ferromagnetic layers which sandwich the non-magnetic layertherebetween, a large magnetoresistance effect is obtained. A multilayerfilm of such a type is called a “spin-valve” (see Phys. Rev. B 45 806(1992), J. Appl. Phys. 69 4774 (1981)). Since the spin-valve cansaturate magnetization in a low magnetic field, the spin-valve issuitable for MR heads. However, since the rate of change in magneticresistance of elements which have been already put to practical use isonly about 20% at the maximum, it is required to improve the rate ofchange in magnetic resistance.

By the way, most of conventional MR elements have a type wherein a sensecurrent is caused to flow in a direction parallel to the plane of an MRfilm constituting the MR element. This is called “CIP (current inplane)”. On the other hand, there is an MR element wherein a sensecurrent is caused to flow in a direction perpendicular to the plane ofan MR film. This is called “CPP (current perpendicular to plane)”. Ithas been reported that CPP can obtain a rate of change in magneticresistance ten times as large as that of CIP (J. Phys. Condens. Matter.11 5717 (1999)), and it is not impossible to obtain a rate of change of100%.

However, if a sense current is caused to flow in a directionperpendicular to the plane of the MR film, there is a problem in thatthe electric resistance is very small, so that the output decreases.Therefore, it has been attempted to decrease the area itself of the MRfilm to raise the value of resistance to increase the output (Phys. Rev.Lett. 70 3343 (1993)). However, in the method for decreasing the areaitself of the MR film, it is limited to cause the MR film to be a singlemagnetic domain.

In addition, if a sense current is caused to flow in a directionperpendicular to the plane of the MR film, an annular magnetic field dueto current is generated in the plane of the MR film. This annularmagnetic field causes to prevent a magnetization free layer, in whichmagnetization rotates with respect to the magnetic field due to signal,from being a single magnetic domain.

On the other hand, most of conventional MR heads have a “shielded”construction wherein an MR film is sandwiched between shields. In thecase of the shielded construction, a floating magnetic field from amagnetic recording medium is directly detected by a spin-valve. However,in recent years, the recording density is further enhanced, so that a“yoke type” head for efficiently incorporating a magnetic flux from amagnetic recording medium into a magnetization free layer of aspin-valve via a magnetic flux guide (yoke) once has been proposed.

However, after the inventor's study, it was revealed that, in manymagnetic heads represented by yoke type magnetic heads, it is requiredto define an active region, in which the detection of magnetism of an MRfilm is carried out, for various reasons.

As an example of this circumstance, a “planar type” head of yoke typeheads will be described below.

FIG. 31 is a schematic perspective view showing the construction of aprincipal part of a planar type head. That is, the planar type head hasa construction that a pair of flat yokes 20, 20 are arranged in parallelto the plane of a recording media 200. An MR film 10 constituting an MRelement is provided so as to be magnetically coupled to the yokes 20,20.

The recording medium 200 is provided with recording bits 200B along arecording track 200T. The magnetic flux due to signal from each of therecording bits 200B is supplied to a magnetic circuit, which is formedby the yoke 20, the MR film 100 and the yoke 20, to be detected.According to such a planar type construction, the length of a magneticpath to the MR film 100 is shortened, so that the magnetic flux can beefficiently led to a spin-valve (see IEEE Trans. Mag. 25, 3689 (1989)).

However, the width 20W of the yoke 20 of the planar type head is widerthan the width 200W of the recording track 200T of the recording mediumwhich has been acceleratively narrowed in recent years. For that reason,it is required to limit the active region of the MR film 100 foractually reading the magnetic flux.

In addition, in the planar type head, it is desired that the magneticpermeability is uniform and great so that the magnetic flux due tosignal from the recording medium 200 efficiently enters the yoke 20without being asymmetric and further enters the magnetization free layerof the MR film 100. Therefore, if a pair of magnetically hard materials30, 30 are arranged so as to be perpendicular to the longitudinaldirections of the track 200T of the medium so that the magnetization ofthe yoke 20 and the magnetization free layer is perpendicular to thetrack direction, the magnetic permeability can be high and uniform.

However, if a CPP type MR element for realizing a high magnetoresistanceeffect is used, it is required to provide an electrode portion (pillarelectrode) for causing a sense current to flow through the MR film in adirection perpendicular thereto. If an annular magnetic field due tocurrent from this electrode portion exceeds a magnetization fixing forcedue to the pair of magnetically hard materials 30, 30, the magnetizationdistribution of the magnetization free layer of the yoke 20 and the MRfilm 100 varies, so that the magnetic permeability is not uniform.

Moreover, if the CPP type MR element is used, the MR film 100 issandwiched between top and bottom electrodes (not shown). Therefore, itwas revealed that the magnetic field due to current from a portion ofthese electrodes parallel to the MR film 100 also influences themagnetization distribution in the yoke 20 and the magnetization freelayer of the MR film 100.

The above described problems are not only caused in the planar typeheads, but the problems are also commonly caused in most of yoke typeheads or heads having other structures. For example, the same problemsare caused in the “shielded” heads.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to eliminate theaforementioned problems and to provide a magnetoresistance effectelement capable of precisely defining the active region of an MR film ina CPP type MR element and of effectively suppressing the influence of amagnetic field due to current from an electrode, and a magnetic head andmagnetic reproducing system using the same.

In order to accomplish the aforementioned object, according to a firstaspect of the present invention, a magnetoresistance effect elementcomprises: a magnetization fixed layer in which the direction ofmagnetization is substantially fixed to one direction; a magnetizationfree layer in which the direction of magnetization varies in response toan external magnetic field; and a non-magnetic intermediate layer formedbetween the magnetization fixed layer and the magnetization free layer,the magnetoresistance effect element having a resistance varying inresponse to a relative angle between the direction of magnetization inthe magnetization fixed layer and the direction of magnetization in themagnetization free layer, the film area of the non-magnetic intermediatelayer being smaller than the film area of each of the magnetizationfixed layer and the magnetization free layer, and a sense currentdetecting the variation of the resistance being applied to the filmplanes of the magnetization fixed layer, the non-magnetic intermediatelayer and the magnetization free layer in a direction substantiallyperpendicular thereto.

According to a second aspect of the present invention, amagnetoresistance effect element comprises: a stacked film including amagnetization fixed layer in which the direction of magnetization issubstantially fixed to one direction, and a magnetization free layer inwhich the direction of magnetization varies in response to an externalmagnetic field; and an electrode connected to a part of a principalplane of the stacked film, the magnetoresistance effect element having aresistance varying in response to a relative angle between the directionof magnetization in the magnetization fixed layer and the direction ofmagnetization in the magnetization free layer, a sense current detectingthe variation of the resistance being applied to the film planes of themagnetization fixed layer and the magnetization free layer via theelectrode in a direction substantially perpendicular to themagnetization fixed layer and the magnetization free layer, and theelectrode comprising a pillar electrode portion substantiallyperpendicularly extending from the principal plane of the stacked film,a first feed portion being connected to the pillar electrode portion andextending from the pillar electrode portion substantially in parallel tothe principal plane of the stacked film, and a second feed portion beingconnected to the first feed portion and extending from the first feedportion substantially in parallel to the principal plane.

According to a third aspect of the present invention, amagnetoresistance effect element comprises: a stacked film including amagnetization fixed layer in which the direction of magnetization issubstantially fixed to one direction, and a magnetization free layer inwhich the direction of magnetization varies in response to an externalmagnetic field; and two electrodes, each of which is connected to a partof a corresponding one of both principal planes of the stacked film, themagnetoresistance effect element having a resistance varying in responseto a relative angle between the direction of magnetization in themagnetization fixed layer and the direction of magnetization in themagnetization free layer, a sense current detecting the variation of theresistance being applied to the film planes of the magnetization fixedlayer and the magnetization free layer via the electrode in a directionsubstantially perpendicular to the magnetization fixed layer and themagnetization free layer, and each of the two electrodes comprising apillar electrode portion substantially perpendicularly extending fromthe corresponding one of the both principal planes of the stacked film,a first feed portion being connected to the pillar electrode portion andextending from the pillar electrode portion substantially in parallel tothe both principal planes of the stacked film, and a second feed portionbeing connected to the first feed portion and extending from the firstfeed portion substantially in parallel to the both principal planes.

According to a fourth aspect of the present invention, amagnetoresistance effect element comprises: a stacked film including amagnetization fixed layer in which the direction of magnetization issubstantially fixed to one direction, and a magnetization free layer inwhich the direction of magnetization varies in response to an externalmagnetic field; and an electrode connected to a part of a principalplane of the stacked film, the magnetoresistance effect element having aresistance varying in response to with a relative angle between thedirection of magnetization in the magnetization fixed layer and thedirection of magnetization in the magnetization free layer, a sensecurrent detecting the variation of the resistance being applied to thefilm planes of the magnetization fixed layer and the magnetization freelayer via the electrode in a direction substantially perpendicular tothe magnetization fixed layer and the magnetization free layer, and theelectrode comprising a pillar electrode portion substantiallyperpendicularly extending from the principal plane of the stacked film,and a feed portion extending substantially in parallel to the principalplane of the stacked film, the pillar electrode portion having twoconductive layers in the central portion and outer peripheral portionthereof, and the sense current being caused to flow in the oppositedirections to each other in the central portion and the outer peripheralportion.

According to a fifth aspect of the present invention, amagnetoresistance effect element comprises: a stacked film including amagnetization fixed layer in which the direction of magnetization issubstantially fixed to one direction, and a magnetization free layer inwhich the direction of magnetization varies in response to an externalmagnetic field; and an electrode connected to a part of a principalplane of the stacked film, the magnetoresistance effect element having aresistance varying in response to a relative angle between the directionof magnetization in the magnetization fixed layer and the direction ofmagnetization in the magnetization free layer, a sense current detectingthe variation of the resistance being applied to the film planes of themagnetization fixed layer and the magnetization free layer via theelectrode in a direction substantially perpendicular to themagnetization fixed layer and the magnetization free layer, and theelectrode comprising a pillar electrode portion substantiallyperpendicularly extending from the principal plane of the stacked film,and a feed portion extending substantially in parallel to the principalplane of the stacked film, the magnetoresistance effect element furthercomprising a magnetic shield provided around the pillar electrodeportion.

According to a sixth aspect of the present invention, a magnetic headcomprises: a pair of yokes arranged so as to face each other via amagnetic gap; and a magnetoresistance effect element magneticallycoupled to the pair of yokes, the pair of yokes having magnetizationarranged in a predetermined direction, and the magnetoresistance effectelement comprising: a stacked film including a magnetization fixed layerin which the direction of magnetization is substantially fixed to onedirection, and a magnetization free layer in which the direction ofmagnetization varies in response to an external magnetic field; and anelectrode connected to a part of a principal plane of the stacked film,the magnetoresistance effect element having a resistance varying inresponse to a relative angle between the direction of magnetization inthe magnetization fixed layer and the direction of magnetization in themagnetization free layer, a sense current detecting the variation of theresistance being applied to the film planes of the magnetization fixedlayer and the magnetization free layer via the electrode in a directionsubstantially perpendicular to the magnetization fixed layer and themagnetization free layer, and the shape of a connecting portion forconnecting the principal plane to the electrode having an edge portionbeing inclined in a magnetization rotating direction of themagnetization free layer from a direction perpendicular to themagnetizing direction of the yokes.

According to a seventh aspect of the present invention, a magnetic headcomprises: a pair of yokes arranged so as to face each other via amagnetic gap; and a magnetoresistance effect element magneticallycoupled to the pair of yokes, the pair of yokes having magnetizationbeing arranged in a predetermined direction, and the magnetoresistanceeffect element comprising: a first stacked film including amagnetization fixed layer in which the direction of magnetization issubstantially fixed to one direction; a second stacked film including amagnetization free layer in which the direction of magnetization variesin response to an external magnetic field; and a non-magneticintermediate layer provided between the first stacked layer and thesecond stacked layer, the magnetoresistance effect element having aresistance varying in response to a relative angle between the directionof magnetization in the magnetization fixed layer and the direction ofmagnetization in the magnetization free layer, the area of a contactportion of a principal plane of the first stacked film contacting thenon-magnetic intermediate layer being smaller than the area of theprincipal plane of the first stacked film, and the area of a contactportion of a principal plane of the second stacked film contacting thenon-magnetic intermediate layer being smaller than the area of theprincipal plane of the second stacked film, a sense current detectingthe variation of the resistance being applied to the film planes of themagnetization fixed layer, the non-magnetic intermediate layer and themagnetization free layer in a direction substantially perpendicularthereto, the shape of a connecting portion for connecting thenon-magnetic intermediate layer to the principal plane of the firststacked film having an edge portion being inclined in a magnetizationrotating direction of the magnetization free layer from a directionperpendicular to the magnetizing direction of the yokes.

According to an eighth aspect of the present invention, a magnetic headcomprises: a pair of yokes being arranged so as to face each other via amagnetic gap; and a magnetoresistance effect element provided on thepair of yokes and magnetically coupled to the pair of yokes, the pair ofyokes having magnetization arranged in a predetermined direction, andthe magnetoresistance effect element comprising: a stacked filmincluding a magnetization fixed layer in which the direction ofmagnetization is substantially fixed to one direction, and amagnetization free layer in which the direction of magnetization variesin response to an external magnetic field; a top electrode connected toa part of an upper principal plane of the stacked film; a bottomelectrode connected to a lower principal plane of the stacked film, themagnetoresistance effect element having a resistance varying in responseto a relative angle between the direction of magnetization in themagnetization fixed layer and the direction of magnetization in themagnetization free layer, a sense current detecting the variation of theresistance being applied to the film planes of the magnetization fixedlayer and the magnetization free layer via the electrode in a directionsubstantially perpendicular to the magnetization fixed layer and themagnetization free layer, the top electrode having a pillar electrodeportion substantially perpendicularly extending from the principal planeof the stacked film, and a feed portion extending substantially inparallel to the principal plane of the stacked film, the bottomelectrode extending in a direction perpendicular to the direction ofmagnetization of the yokes, the feed portion of the top electrode beingprovided so that the sense current flowing through the feed portion isanti-parallel to a sense current flowing through the bottom electrode.

In the magnetic head according to any one of the above described sixththrough eighth aspects, a method for applying magnetization, which isarranged in a predetermined direction, to the pair of yokes may be amethod for annealing the yokes in a magnetic field, or a method forapplying a magnetic field due to bias which is caused by a biasing filmof a magnetically hard film or an antiferromagnetic film.

According to a ninth aspect of the present invention, a magnetic headhas a magnetoresistance effect element according to any one of the abovedescribed first through fifth aspect.

According to a tenth aspect of the present invention, a magneticreproducing system has any one of the above described magnetic head, andis capable of reading magnetic information stored in a magneticrecording medium.

In other words, according to another aspect of the present invention, amagnetoresistance effect film wherein a current is applied to theelement in a direction perpendicular to the film surface of the elementand which comprises: at least one magnetization free layer in whichmagnetization rotates in response to an external magnetic field; and atleast one magnetization pinned layer in which magnetization is fixed,wherein a pillar electrode is provided between a portion for allowing asense current to flow in parallel to the film surface of the element ofthe electrode and the element, the sectional area of a portion of thepillar electrode contacting the element being smaller than the area ofany portion of the element.

According to another aspect of the present invention, amagnetoresistance effect film wherein a current is applied to theelement in a direction perpendicular to the film surface of the elementand which comprises: at least one magnetization free layer in whichmagnetization rotates in accordance with an external magnetic field; andat least one magnetization pinned layer in which magnetization is fixed,wherein a pillar electrode is provided between a portion for allowing asense current to flow in parallel to the film surface of the element ofthe electrode and the element, the sectional area of a portion of thepillar electrode contacting the element being smaller than the area ofany portion of the element if being viewed from an approaching directionof a magnetic field due to signal or a direction perpendicular to theapproaching direction.

In the magnetoresistance effect element according to the second aspect,the sectional area of the pillar portion may substantially linearlyincrease from a surface contacting the element toward a surface of aportion in which a current flows in parallel and which contacts theelectrode.

Alternatively, in the magnetoresistance effect element according to thesecond aspect, the sectional area of the pillar portion may simplyincrease from a surface contacting the element toward a surface in whicha current flows in parallel to the film surface of the element and whichcontacts the electrode, and its increasing rate may vary on the way.

Alternatively, in the magnetoresistance effect element according to thesecond aspect, the pillar portion may be divided into two portionshaving a small rate of change in sectional area.

Moreover, the contact area of the pillar portion contacting themagnetoresistance effect film may be S_(Lead)/S_(MR)>2000 assuming thatthe contact area of the pillar portion contacting the feed portion isS_(Lead).

Alternatively, of the two portions having the small rate of change insectional area, the height of a portion having a small mean sectionalarea may be 30 nm or less.

In addition, the electrode area of a portion of the bottom and topelectrodes contacting the pillar electrode may be narrowed so as to bethe same as the sectional area of the pillar electrode.

That is, in the case of a CPP element, the active region of the MRelement is defined by the area of a portion, in which a sense currentflows, of a ferromagnetic/non-magnetic interface which mainly providesthe magnetoresistance effect element. In the case of a CPP type MR, thesectional area of the pillar electrode must be smaller than the size ofthe element in order to increase the electrical resistance whilemaintaining the magnetic characteristics of the MR element. By thepillar electrode in this case, the active region of the MR element canbe defined.

In addition, in order to decrease the magnetic field due to current fromthe pillar electrode, the sectional area of the pillar electrode isvaried to decrease the area of a surface contacting the element.Moreover, the pillar electrode is formed by two portions in which thesectional area does not so vary, and the sectional area and height of aportion contacting the element are defined to be predetermined ranges.If the magnetic field due to current from the pillar electrode isdecreased to be smaller than the magnetization fixing force due to apair of magnetically hard materials, the magnetization in the yokes andthe magnetization free layer of the MR element does not so rotate. Forthat reason, the magnetic flux from the recording medium substantiallysymmetrically enters the magnetization free layer.

Alternatively, the sense current is caused to go and return in thepillar electrode to prevent the magnetic field due to current from beingapplied, so that the magnetic field due to the sense current iscanceled. Alternatively, a magnetic shield is provided around the pillarelectrode to prevent the magnetic field due to current from beingapplied to the element. If the current is caused to go and return in thepillar electrode, the magnetic field due to current to the outside ofthe electrode is canceled. In addition, if the shield is provided, themagnetic field due to current is not applied to the element and theyokes. Therefore, the magnetic flux from the recording mediumsymmetrically enter the magnetization free layer.

Moreover, in the case of a planar yoke head, the magnetization of theyokes may rotate due to the influence of the magnetic field due tocurrent which could not have been removed. In this case, there is somepossibility that the magnetization of the yokes may be deviated from adirection parallel to the track longitudinal direction of the recordingmedium to read a magnetic flux due to signal from an adjacent track. Inorder to prevent this, the shape of the cross section of the pillarelectrode or the pillar non-magnetic material for defining the activeregion of the element is designed to extend along the flow of themagnetic flux so as to efficiently read only a signal from a trackdirectly below the active region. When the magnetic field due to currentfrom the pillar electrode can not be ignored, the magnetic flux from therecording medium asymmetrically enters the yokes and the magnetizationfree layer of the MR element to some extent. In expectation of this, ifthe cross section of the pillar electrode is designed to be asymmetricso as to extend along the flow of the magnetic flux, the regenerativeefficiency is improved.

In addition, the electrode is arranged so that the current applyingdirection in an electrode portion parallel to the plane of the elementis parallel to the track direction of the medium. According to such anarrangement, the direction of the magnetic field due to current fromthis portion is the same direction as the magnetization fixing directionof the yokes and magnetization free layer due to the pair ofmagnetically hard materials. In addition, if the direction of current inthe top electrode is anti-parallel to that in the bottom electrode, themagnetic field due to current applied to the yokes can be reduced. Ifthe electrode in a portion parallel to the plane of the element isparallel to the track direction, the magnetic field due to current isgenerated in a direction perpendicular to the track. Since thisdirection is the same as the magnetization fixing direction due to thepair of magnetically hard materials, there is no influence on themagnetization distribution in the yokes and magnetization free layer.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood more fully from the detaileddescription given herebelow and from the accompanying drawings of theembodiments of the invention. However, the drawings are not intended toimply limitation of the invention to a specific embodiment, but are forexplanation and understanding only.

In the drawings:

FIGS. 1(a) and 1(b) are sectional and plan views showing the firstembodiment of a magnetoresistance effect element according to thepresent invention;

FIG. 2 is a conceptual drawing showing a first modified example of amagnetoresistance effect element in the first embodiment;

FIG. 3 is a conceptual drawing showing a second modified example of amagnetoresistance effect element in the first embodiment;

FIG. 4 is a conceptual drawing showing a current path in amagnetoresistance effect film 13;

FIG. 5 is a conceptual drawing showing a sectional construction of athird modified example of a magnetoresistance effect element in thefirst embodiment;

FIG. 6 is a conceptual drawing showing a principal part of a shieldedhead on which the magnetoresistance effect element illustrated in FIG. 1is mounted;

FIG. 7 is a conceptual drawing showing a magnetization distribution in amagnetization free layer (free layer) of a magnetoresistance effectelement;

FIG. 8 is a perspective view showing a construction wherein themagnetoresistance effect element illustrated in FIG. 1 is mounted on aplanar yoke head;

FIG. 9 is a conceptual drawing showing a magnetizing direction in thethird embodiment of a head according to the present invention;

FIG. 10 is a perspective view showing the construction of a principalpart of a modified example of a magnetic head in the third embodiment;

FIG. 11 is a sectional view of the magnetoresistance effect element inthe third embodiment of the present invention, which is provided with anauxiliary yoke;

FIG. 12(a) is a perspective view showing a magnetic field due tocurrent, which is generated when a sense current is caused to flow, andthe direction of a magnetic field due to bias based on a magneticallyhard film or an antiferromagnetic film, in the first embodiment of amagnetoresistance effect element according to the present invention, andFIG. 12(b) is a characteristic graph of the magnitude of an annularmagnetic field due to current, which is generated in a magnetoresistanceeffect film when a sense current of 5 mA is caused to flow, with respectto the distance from the center of a pillar electrode;

FIG. 13(a) is a perspective view showing a magnetic field due tocurrent, which is generated when a sense current is caused to flow, andthe direction of a magnetic field due to bias based on a magneticallyhard film or an antiferromagnetic film, in the first embodiment of amagnetoresistance effect element according to the present invention, andFIG. 13(b) is a characteristic graph of the magnitude of an annularmagnetic field due to current, which is generated in a magnetoresistanceeffect film when a sense current of 5 mA is caused to flow, with respectto the distance from the center of a pillar electrode;

FIG. 14 is a sectional view of the fourth embodiment of amagnetoresistance effect element according to the present invention;

FIG. 15 is a schematic diagram showing a modified example 4-1 of amagnetoresistance effect element in the fourth embodiment of the presentinvention, wherein the sectional area of a pillar electrode is linearlyvaried from one surface contacting a top electrode to the other surfacecontacting the magnetoresistance effect film;

FIG. 16 is a schematic diagram showing a modified example 4-2 of amagnetoresistance effect element in the fourth embodiment of the presentinvention, wherein the magnetoresistance effect element is capable ofbeing generally divided into two parts by the sectional area of a pillarelectrode;

FIG. 17 is a schematic view of the fifth embodiment of amagnetoresistance effect element according to the present invention;

FIG. 18 is a schematic view of the sixth embodiment of amagnetoresistance effect element according to the present invention;

FIG. 19 is a plan view of a magnetoresistance effect element when a CPPtype GMR film is mounted on a planar yoke head, wherein a magnetizationdistribution in a yoke and a magnetization free layer is described byarrows and a traveling direction of a magnetic flux due to signal in thecase of the magnetization distribution is shown, FIG. 19(a) showing amagnetization distribution and the flow of a magnetic flux due to signalwhen the influence of a magnetic field due to a sense current flowingthrough a pillar electrode can be ignored, FIG. 19(b) showing amagnetization distribution and the flow of a magnetic flux due to signalwhen the sense current of the column electrode can not be ignored, andFIG. 19(c) showing the flow of a magnetic flux due to signal when thesense current of the pillar electrode can not be ignored, and theposition and shape of the pillar electrode suitable therefor, as theseventh embodiment of the present invention;

FIG. 20 is a perspective view of the eighth embodiment of amagnetoresistance effect element according to the present invention;

FIG. 21 is a plan view of the eighth embodiment of a magnetoresistanceeffect element according to the present invention, wherein amagnetization distribution in a yoke and a magnetization free layer, theflow of a magnetic flux due to signal determined by the distribution,and the position and shape of a pillar electrode suitable for the floware shown;

FIG. 22 is an illustration showing the details of the shape of thepillar electrode shown in FIG. 21;

FIG. 23 is an illustration for explaining the sectional shape of apillar electrode of a magnetoresistance effect element when the seventhand eighth embodiments of the present invention are combined;

FIG. 24 is a perspective view of the ninth embodiment of amagnetoresistance effect element according to the present invention;

FIG. 25 is a plan view of a top electrode in the ninth embodiment of thepresent invention, wherein current paths and a magnetic field due tocurrent generated in a magnetoresistance effect film by the currentpaths are shown by arrows;

FIG. 26 is a perspective view of a modified example 9-1 of amagnetoresistance effect film, wherein the top and bottom electrodes inthe ninth embodiment of the present invention are narrowed at theposition of a pillar electrode;

FIG. 27 is an illustration wherein current paths in a top electrode in amodified example of the present invention, and a magnetic field due tocurrent generated in a magnetoresistance effect film by the currentpaths are shown by arrows;

FIG. 28 is a perspective view illustrating the schematic construction ofa principal part of a magnetic reproducing system according to thepresent invention;

FIG. 29 is an enlarged perspective view of a magnetic head assembly infront of an actuator arm 155, viewed from the side of a disk;

FIG. 30(a) is a conceptual drawing showing the relationship between ahead slider 153 and a magnetic head 200 when a flying height is apredetermined positive value, and FIG. 30(b) is a conceptual drawingshowing the relationship between such a “contact traveling” the headslider 153 and the magnetic head 200; and

FIG. 31 is a schematic perspective view showing the construction of aprincipal part of a planar type head.

DESCRIPTION OF THE EMBODIMENTS

Referring now to the accompanying drawings, the embodiments of thepresent invention will be described below.

First Embodiment

First, as the first embodiment of the present invention, the basicconstruction for restricting a current applying region to an MR filmwill be described below.

FIG. 1 is a conceptual drawing showing the construction of a principalpart of a magnetoresistance effect element in this embodiment. That is,FIG. 1(a) is its sectional view, and FIG. 1(b) is its plan view. Theright side in FIG. 1 corresponds to an external magnetic fieldapproaching surface. For example, if the magnetoresistance effectelement is mounted on a shielded head, the external magnetic fieldapproaching surface is arranged so as to face a magnetic recordingmedium, and if the magnetoresistance effect element is mounted on aplanar type head, the external magnetic field approaching surface issupported on one of magnetic yokes.

In this embodiment, an MR element 10 comprises a bottom electrode 12, amagnetoresistance effect film 13, a pillar electrode 14 and a topelectrode 15 which are stacked on a substrate 11 in that order. Theseare surrounded by an insulating material (not shown). Themagnetoresistance effect film 13 has a stacked construction wherein amagnetization fixed layer (pinned layer), non-magnetic intermediatelayer (spacer layer) and magnetization free layer (free layer) (notshown) are stacked. One embodiment of the present invention ischaracterized in that the sectional area of the pillar electrode 14 issmaller than the sectional area of each of the layers constituting themagnetoresistance effect film 13.

A sense current is caused to flow from the top electrode 15 to thepillar electrode 14, the magnetoresistance effect film 13 and the bottomelectrode 12, or in the opposite direction thereto. That is, withrespect to the magnetoresistance effect film 13, the sense current flowsin a direction perpendicular to the plane of the film.

Although the magnetoresistance effect film 13 is basically made of ametal, most of the sense current flows through a region contacting thepillar electrode 14. By utilizing this, an active region 13A can bedefined by the sectional shape of the pillar electrode 14.

Although the shape of the active region 13A in which the pillarelectrode 14 contacts the magnetoresistance effect film 13 may be anyshape, it is effectively a shape approximating to a rectangle as shownin FIG. 1(b) in order to efficiently read a magnetic field due to signalfrom a magnetic recording medium.

MODIFIED EXAMPLE 1-1

FIG. 2 is a conceptual drawing showing a first modified example of amagnetoresistance effect element in this embodiment. That is, FIG. 2(a)is its sectional view, and FIG. 2(b) is its plan view.

As shown in FIG. 2, the magnetoresistance effect element 10A in thismodified example comprises a bottom electrode 12, a pillar electrode 14,a magnetoresistance effect film 13 and a top electrode 15 which arestacked on a substrate 11 in that order. In such a magnetoresistanceeffect element, an active region 13A can be similarly defined.

Although the shape of the active region 13A in which the pillarelectrode 14 contacts the magnetoresistance effect film 13 may be anyshape, it is effectively a shape approximating to a rectangle as shownin FIG. 2(b) in order to efficiently read a magnetic field due to signalfrom a magnetic recording medium.

MODIFIED EXAMPLE 1-2

FIG. 3 is a conceptual drawing showing a second modified example of amagnetoresistance effect element in this embodiment. That is, FIG. 2(a)is its sectional view, and FIG. 2(b) is its plan view. Themagnetoresistance effect element 10B in this modified example comprisesa bottom electrode 12, a bottom pillar electrode 14A, amagnetoresistance effect film 13, a top pillar electrode 14B and a topelectrode 15 which are stacked on a substrate 11 in that order.

FIG. 4 is a conceptual drawing showing a current path in themagnetoresistance effect element 13.

In the magnetoresistance effect elements shown in FIGS. 1 and 2, acomponent parallel to the plane of the magnetoresistance effect film 13is generated in a current distribution in the film as shown in FIG.4(a), so that the element is not a complete CPP type MR element.

As compared with this, in the second modified example shown in FIG. 3,the component parallel to the plane of the magnetoresistance effect film13 disappears in the current distribution in the film as shown in FIG.4(b), so that the CPP type MR element can be extracted. In addition, theactive region 13A of the magnetoresistance effect film can be moreeffectively defined.

Although the shape of the active region 13A in which the top pillarelectrode 14B and the bottom pillar electrode 14A contact themagnetoresistance effect film 13 may be any shape, it is effectively ashape approximating to a rectangle as shown in FIG. 3(b) in order toefficiently read a magnetic field due to signal from a magneticrecording medium.

MODIFIED EXAMPLE 1-3

FIG. 5 is a conceptual drawing showing a sectional construction of athird modified example of a magnetoresistance effect element in thisembodiment. That is, in the magnetoresistance effect element 10C in thismodified example, a non-magnetic intermediate layer 13S of a spin-valvewhich has a stacked film 13P having at least one magnetization fixedlayer (pinned layer) and a stacked film 14F having at least onemagnetization free layer (free layer) is patterned in the form of apillar. However, the stacking order in this figure should not limited.Furthermore, electrodes (not shown) contact the top and bottom faces ofthe magnetoresistance effect film 13.

The interface between the non-magnetic intermediate layer 13S and themagnetization fixed layer and the interface between the non-magneticintermediate layer 13S and the magnetization free layer have theinterfacial effect of the magnetoresistance effect. In the element shownin FIG. 5, a current flows in a direction substantially perpendicular tothese interfaces, so that the effects of a CPP type GMR can beextracted.

Although the shape of the active region in which the pillar spacer layer13S contacts the pinned layer 13P and the free layer 13S may be anyshape, it is effectively a shape approximating to a rectangle in orderto efficiently read a magnetic field due to signal from a magneticrecording medium.

Second Embodiment

As the second embodiment of the present invention, an embodiment of thestructure shown in FIG. 1 which is applied to a shielded head will bedescribed below.

FIG. 6 is a conceptual drawing showing a principal part of a shieldedhead on which the magnetoresistance effect element illustrated in FIG. 1is mounted. That is, FIG. 6(a) is a sectional view taken along alongitudinal direction of a recording track, and FIG. 6(b) is asectional view taken along a cross direction of a recording track. Inthe figure, a magnetic recording medium 200 travels in directions ofarrow A.

In the magnetic head in this embodiment, a magnetoresistance effect film13 is sandwiched between a pair of magnetic shields 24 and 24, and isarranged so as to be perpendicular to the magnetic recording medium 200.In addition, a top electrode 12, a pillar electrode 14 and a topelectrode 15 are provided as shown in the figure, so that an activeregion 13A is defined.

FIG. 7 is a conceptual drawing a magnetization distribution in amagnetization free layer (free layer) of the magnetoresistance effectfilm 13. A magnetic flux due to signal from the recording medium 13enters the magnetization free layer of the magnetoresistance effectelement 13 to rotate the magnetization of the magnetization free layer.Usually, in no magnetic field, as shown in FIG. 7(a), the magnetization(arrows) of the magnetization free layer is formed as a single magneticdomain by a magnetic field due to bias from a biasing film 30 so as tobe perpendicular to an approaching magnetic field. If a magnetic flux Fenters herein from the recording medium, the magnetization (arrows) ofthe magnetization free layer rotates as shown in FIG. 7(b), but therotation angle thereof attenuates as the distance from the recordingmedium 200 increases. That is, the sensitivity is higher in a portionnearer to the recording medium 200.

Therefore, if the pillar electrode 14 is arranged in a portion nearer tothe recording medium 200, only a portion having a high sensitivity ofthe magnetization free layer can be an active region 13A, so that it ispossible to realize a high output.

Furthermore, in the construction of FIG. 6, each of the top electrode 15and the bottom electrode 12 may also serve as a magnetic shield. In thatcase, the structure is simplified, and the fabricating process isshortened.

In FIG. 6, the magnetoresistance effect element may be an element in theabove described modified example 1-1, 1-2 or 1-3.

Third Embodiment

As the third embodiment of the present invention, a planar yoke headhaving a bias applying means will be described below.

FIG. 8 is a perspective view showing the construction of a planar yokehead on which the magnetoresistance effect element illustrated in FIG. 1is mounted. In this figure, the same reference numbers are given to thesame element as those described above referring to FIGS. 1 through 7 and31 to omit the detailed descriptions thereof. Furthermore, in thisfigure, top and bottom electrodes in a portion parallel to the plane ofthe film are omitted.

In this embodiment, a pair of yokes 20, 20 are sandwiched between a pairof biasing films 30 and 30 formed of a hard film of a magnetically hardmaterial or an antiferromagnetic film, and the magnetization is formedas a single magnetic domain so as to be directed in a direction of y.Similarly, the magnetization of the magnetization free layer of amagnetoresistance effect film 13 is also aligned with the direction ofy.

FIG. 9 is a conceptual drawing showing a magnetizing direction in thehead in this embodiment.

As shown in this figure, a magnetic flux from a magnetic recordingmedium 200 mainly enters the yoke 20 in a portion above a track 200T,and the magnetization of the magnetization free layer is also greatlyrotate only in the portion above the track 200T. Therefore, if thesectional area of a pillar electrode 14 is limited to a track width 200Was shown in FIG. 8 so that only a portion having a high sensitivity isan active region 13A (see FIG. 1), it is possible to improve the output.

Furthermore, also in this embodiment, the same effects can be obtainedeven if the magnetoresistance effect element in the above describedmodified example 1-1, 1-2 or 1-3 is mounted.

MODIFIED EXAMPLE 3-1

As a first modified example of this embodiment, a construction forapplying a magnetic field due to bias to a yoke and a magnetization freelayer will be described below.

FIG. 10 is a schematic perspective view showing the construction of aprincipal part of a magnetic head in this modified example. Also in thisfigure, the same reference numbers are given to the same elements asthose described above referring to FIGS. 1 through 9 and 31 to omit thedetailed descriptions thereof.

In this modified example, a pair of biasing films 30, 30 of amagnetically hard film or an antiferromagnetic film are arranged onyokes 20 and a magnetization free layer. According to such a “patternedbias construction”, an ideal magnetic field due to bias can be appliedto the yokes 20 and the magnetization free layer.

MODIFIED EXAMPLE 3-2

As a second modified example of this embodiment, a construction havingauxiliary yokes will be described below.

FIG. 11 is a schematic sectional view showing the construction of aprincipal part of a magnetic head in this modified example. Also in thisfigure, the same reference numbers are given to the same elements asthose described above referring to FIGS. 1 through 10 and 31 to omit thedetailed descriptions thereof.

In this modified example, auxiliary yokes 22 substantially having thesame size as that of the width 200W of a recording track of a recordingmedium are added to the planar yoke head illustrated in FIG. 8. Thus, amagnetic flux due to signal from the recording track is efficiently ledto the yokes 20, and thus to the magnetization free layer of amagnetoresistance effect element 13. As a result, only the magnetizationof a portion above the recording track ideally rotates, so that anactive region 13A can be more conspicuously defined by arranging apillar electrode 14 within the track width.

Of course, the same effects can be obtained even if the constructionillustrated in any one of FIGS. 10, 20, 24 and 26 is provided with thesame auxiliary yokes 22, 22.

Fourth Embodiment

As the fourth embodiment of the present invention, a concreteconstruction for suppressing the effects of an annular magnetic fieldgenerated by a pillar electrode will be described below.

FIG. 12(a) is a schematic diagram showing a principal part of themagnetoresistance effect element illustrated in FIG. 1. Biasing films 30of a magnetically hard film or an antiferromagnetic film are provided onthe front and rear sides in the figure, so that the magnetization freelayer is formed as a single magnetic domain by a magnetic field due tobias generated by the biasing films 30.

It is assumed that the cross section of the pillar electrode 14 iscircular and its height is infinitely long. If a sense current Is iscaused to flow through such a pillar electrode 14 in a direction ofarrow, an annular magnetic field due to current is applied to themagnetoresistance effect element 13 as shown by arrow M. If the magneticfield M due to current increases to such an extent that it can not beignored, the magnetic permeability of a magnetic flux due to signalentering the magnetization free layer in a lateral direction in thefigure is not uniform on the plane. Moreover, if the magnitude of themagnetic field M due to current exceeds the magnetic field B due tobias, the magnetization of the magnetization free layer rotates.

FIG. 12(b) is a graph showing the magnitude of a magnetic field M due tocurrent at a position, which is spaced from the center of the pillarelectrode 14 by a distance r, when a sense current Is of 5 mA is causedto flow. Furthermore, in this figure, the broken lines show a magneticfield distribution in the pillar electrode 14, and the solid line showsa magnetic field distribution outside of the pillar electrode 14. Thatis, the magnetic field due to current increases in the pillar electrode14 as the distance from the center increases, has a peak on the outerwall of the electrode 14, and attenuates as the distance from the outerwall of the electrode 14 increases outwardly.

The locally applied maximum magnetic field greatly depends on the radiusr of the pillar electrode 14. For example, the maximum magnetic field is25 Oe if the radius is 100 nm, it is 12.5 Oe if the radius is 200 nm,and it is 8.3 Oe if the radius is 300 nm. Thus, the maximum magneticfield due to current decreases as the radius r_(p) increases. It can betherefore said that the radius r_(p) of the pillar electrode 14 ispreferably as large as possible.

FIG. 13(a) is a schematic diagram showing a principal part of themagnetoresistance effect element illustrated in FIG. 1. In this case,biasing films 30 of a magnetically hard film or an antiferromagneticfilm are provided on the front and rear sides in the figure, so that themagnetization free layer is formed as a single magnetic domain by amagnetic field due to bias generated by the biasing films 30.

It is herein assumed that an infinitely thin linear electrode. If asense current Is is caused to flow through such a linear electrode in adirection of arrow, an annular magnetic field is applied to themagnetoresistance effect element 13 as shown by arrow M. If the magneticfield M due to current increases to such an extent that it can not beignored, the magnetic permeability of a magnetic flux F due to signalentering the magnetization free layer in a lateral direction in thefigure is not uniform on the plane. Moreover, if the magnetic field Mdue to current exceeds the magnetic field B due to bias, themagnetization of the magnetization free layer rotates.

FIG. 13(b) is a graph showing the magnitude of a magnetic field M due tocurrent at a position, which is spaced from the pillar electrode 14 by adistance r, when a sense current of 5 mA is caused to flow. Themagnitude of the magnetic field M due to current greatly depends on theheight h of the pillar electrode 14. For example, at a position of r=0.2μm, the magnitude of the magnetic field M due to current is 1.25 Oe ifthe height h is 10 nm, it is 7.18 Oe if the height h is 60 nm, and it is17.7 Oe if the height h is 200 nm. Thus, the magnitude of the magneticfield M due to current decreases as the height h increases. Because theintensity of the magnetic field M due to current at the position of themagnetoresistance effect film 13 is determined by the integral alonglongitudinal directions of the pillar electrode 14. It can be thereforesaid that the height h of the pillar electrode 14 must be designed to besmallish.

In view of the foregoing, the pillar electrode 14 is designed asfollows.

First, the pillar electrode 14 must be thick in order to suppress themagnetic field M due to current. On the other hand, the sectional areaof the pillar electrode 14 on a plane contacting the magnetoresistanceeffect film 13 is preferably small from the standpoint of the narrowingof the active region 13A and from the standpoint of the enhancement ofthe resistance of the CPP type GMR element.

In addition, the magnetic field M due to current can be reduced as thelength of the pillar electrode 14 decreases. However, the height h ofthe pillar electrode 14 must be at least about 100 nm in order to ensurethe electrical insulation between the magnetoresistance effect film 13,the top electrode 15 and the bottom electrode 12.

As a design simultaneously satisfying these conditions, for example, inthe case of the magnetoresistance effect element illustrated in FIG. 1,the sectional area of a portion of the pillar electrode 14 near the topelectrode 15 may be large, and the sectional area of a portion of thepillar electrode 14 near the magnetoresistance effect film 13 may besmall.

FIG. 14 is a conceptual drawing illustrating this construction. It canbe also seen from FIG. 12 that the magnetic field due to current issmall in a portion 14L having a large sectional area even if its heightis large. Therefore, only the magnetic field M due to current from aportion 14S having a narrowed sectional area near the magnetoresistanceeffect film 13 may be substantially considered. In this case, the crosssection in horizontal directions may have a shape of circle, or any oneof other various shapes as will be described later in detail.

An example where this pillar electrode 14 is applied to the modifiedexample 1-2 is shown in FIG. 14(b). This example is more effective sincethe contribution of two pillar electrodes is moderated.

This pillar electrode 14 can be also applied to the magnetoresistanceeffect element in the modified example 1-1. Since the rotation ofmagnetization according to a magnetic field due to signal from amagnetic recording medium is carried out in a magnetization free layer,if the area of a pillar non-magnetic intermediate layer contacting themagnetization free layer is smaller than the area of the pillarnon-magnetic intermediate layer contacting a magnetization fixed layeras shown in FIG. 14(c), it is possible to enhance its sensitivity.

In addition, if the area of the pillar non-magnetic intermediate layercontacting the magnetization fixed layer is smaller than the area of thepillar non-magnetic intermediate layer contacting the magnetization freelayer as shown in FIG. 14(d), unnecessary magnetic field is not appliedto the magnetization fixed layer, so that it is possible to improve themagnetization stability in the magnetization fixed layer.

MODIFIED EXAMPLE 4-1

FIG. 15 is a conceptual drawing showing a construction wherein thesectional area of the pillar electrode 14 is linearly varied from onesurface contacting the top electrode 15 to the other surface contactingthe magnetoresistance effect film 13. Such a pillar electrode 14 can beprepared by one lift off if a tapered resist is used. Of course, thispillar electrode 14 can also be applied to the magnetoresistance effectelement in any one of the modified example 1-1 and 1-2.

An example where this pillar electrode 14 is applied to the modifiedexample 1-2 is shown in FIG. 15(b). This example is more effective sincethe contribution of two pillar electrodes is moderated.

This pillar electrode 14 can be also applied to the magnetoresistanceeffect element in the modified example 1-1. Since the rotation ofmagnetization according to a magnetic field due to signal from amagnetic recording medium is carried out in a magnetization free layer,if the area of a pillar non-magnetic intermediate layer contacting themagnetization free layer is smaller than the area of the pillarnon-magnetic intermediate layer contacting a magnetization fixed layeras shown in FIG. 15(c), it is possible to enhance its sensitivity.

In addition, if the area of the pillar non-magnetic intermediate layercontacting the magnetization fixed layer is smaller than the area of thepillar non-magnetic intermediate layer contacting the magnetization freelayer as shown in FIG. 15(d), unnecessary magnetic field is not appliedto the magnetization fixed layer, so that it is possible to improve themagnetization stability in the magnetization fixed layer.

MODIFIED EXAMPLE 4-2

FIG. 16 is a conceptual drawing illustrating a construction wherein thesectional area of the pillar electrode 14 is generally divided into twostages. Thus, it is possible to increase the difference between the areaS_(MR) of a surface of the pillar electrode 14 contacting themagnetoresistance effect film 13 and the area S_(upperlead) of a surfaceof the pillar electrode 14 contacting the top electrode 15. As thisdifference increases, the magnetic field M due to current from a portionof the pillar electrode 14 having a large sectional area can be reduced.By the inventor's study, it was revealed that the pillar electrode 14 ispreferably designed so that S_(upperlead)/S_(MR)>2000.

However, even if the pillar electrode 14 is thus designed, if theportion having the small sectional area is long, the magnetic field Mdue to current increases as described above referring to FIGS. 13(a) and13(b). Therefore, the height of the portion having the small sectionalarea is preferably 30 nm or less, and more preferably 15 nm or less.

An example where this pillar electrode 14 is applied to the modifiedexample 1-2 is shown in FIG. 16(b). This example is more effective sincethe contribution of two pillar electrodes is moderated.

This pillar electrode 14 can be also applied to the magnetoresistanceeffect element in the modified example 1-1. Since the rotation ofmagnetization according to a magnetic field due to signal from amagnetic recording medium is carried out in a magnetization free layer,if the area of a pillar non-magnetic intermediate layer contacting themagnetization free layer is smaller than the area of the pillarnon-magnetic intermediate layer contacting a magnetization fixed layeras shown in FIG. 16(c), it is possible to enhance its sensitivity.

In addition, if the area of the pillar non-magnetic intermediate layercontacting the magnetization fixed layer is smaller than the area of thepillar non-magnetic intermediate layer contacting the magnetization freelayer as shown in FIG. 16(d), unnecessary magnetic field is not appliedto the magnetization fixed layer, so that it is possible to improve themagnetization stability in the magnetization fixed layer.

Fifth Embodiment

As the fifth embodiment of the present invention, a construction whereinthe magnetic field due to current in a pillar electrode is canceled.

FIG. 17 is a conceptual drawing illustrating the construction of aprincipal part of a magnetoresistance effect element in this embodiment.That is, FIG. 17(a) is a drawing of its longitudinal section, and FIG.17(b) is a drawing of horizontal section of its principal part.

This embodiment is characterized in that, in the constructionillustrated in FIG. 1, the pillar electrode 14 is divided into a centralconductive portion 14C and an outer peripheral conductive portion 14P,and a sense current Is is caused to go and return to cancel a magneticfield M due to current. The central conductive portion 14 and the outerperipheral conductive portion 14P are insulated from each other by meansof an insulator 14I.

The sense current Is flows from a top electrode approach route 12A intothe central conductive portion 14C to be applied to themagnetoresistance effect film 13 in a direction perpendicular thereto.Then, the sense current Is flows from a bottom electrode approach route12A to a return route 12B arranged on the magnetoresistance effect filmto pass through the outer peripheral conductive portion 14P to a topelectrode return route 15B. Of course, the sense current Is may flow inthe opposite direction. If the sense current Is is thus caused go andreturn in the pillar electrode 14, the magnetic field M due to currentapplied to the magnetoresistance effect film 13 can be reduced, and canbe ideally zero.

Of course, this can also be similarly applied to the modified examples1-1 and 1-2 illustrated in FIGS. 2 and 3.

Sixth Embodiment

As the sixth embodiment of the present invention, a construction whereina magnetic field due to current in a pillar electrode is shielded willbe described below.

FIG. 18 is a conceptual drawing illustrating the construction of aprincipal part of a magnetoresistance effect element in this embodiment.That is, FIG. 18(a) is a drawing of its longitudinal section, and FIG.18(b) is a drawing of horizontal section of its principal part.

In this embodiment, a magnetic shield 15 is arranged around a pillarelectrode 14 via an insulator 14I. If such a magnetic shield 15 isprovided, the magnetic field M due to current applied to themagnetoresistance effect film 13 can be reduced, and can be ideallyzero.

Seventh Embodiment

In the fourth through sixth embodiments, the design of the element forreducing or suppressing the influence of the annular magnetic field Mdue to current from the pillar electrode has been described.

This embodiment relates to an approach to the avoidance of a crosstalkfrom an adjacent track during reading, which is caused by a magneticfield M due to current.

FIG. 19 is a conceptual drawing showing a plane construction of a planaryoke head on which a CPP type GMR element is mounted.

FIG. 19(a) shows a magnetization distribution (arrows) when theinfluence of a magnetic field M due to current is small to an extentthat it can be ignored. Biasing films 30, 30 of a magnetically hard filmor an antiferromagnetic film are provided, so that each of themagnetization free layer 13F of a magnetoresistance effect film andyokes 20 is formed as a single magnetic domain by a magnetic field B dueto bias generated by the biasing films 30, 30. Thus, the magneticpermeability with respect to a track longitudinal direction T in anyportion of the magnetization free layer 13F and the yokes 20 is maximum,so that magnetization enters only in the track longitudinal direction T.In addition, the magnetic permeability on the track is maximum, so thatonly the magnetization on the track clearly rotates.

FIG. 19(b) shows a magnetization distribution when a reflux current Mremains to have the same intensity as that of a magnetic field B due tobias. In this case, the magnetization (arrows) of the magnetization freelayer 13F and the yokes 20 rotates as shown in the figure. At this time,the magnetization (arrows) is deviated from the cross direction of thetrack 200T in a portion deviated from the track 200T, so that thedirection of a high magnetic permeability is not the track longitudinaldirection in some place. At this time, there is some possibility that amagnetic flux F due to signal from an adjacent side track 200ST mayenter in a direction perpendicular to magnetization to generate acrosstalk to deteriorate off track characteristics. In other words, themagnetization distribution of the magnetization free layer 13F and theyokes 20 is changed by the magnetic field M due to current to form amagnetic permeable lens, so that the magnetic flux from the adjacenttrack also converges.

In order to prevent the readout of such a converging magnetic flux fromthe adjacent track, the cross section of the pillar electrode 14 mayhave a shape of trapezoid as illustrated in FIG. 19(c). Thus, themagnetic flux F from the side track does not enter the active region 13Aof the magnetoresistance effect film, so that off track characteristicsare improved.

In this case, when the direction of the magnetic field B due to bias is+y direction and when the direction of the sense current Is is −zdirection, the positional relationship is required so that the shorterside of the trapezoid is arranged on the side of +x and the longer sidethereof is arranged on the side of −x.

MODIFIED EXAMPLE 7-1

If the shape of the cross section of the pillar intermediatenon-magnetic film 13S in the modified example 1-3 illustrated in FIG. 5is the same trapezoid as that illustrated in FIG. 19, off trackcharacteristics can be improved.

Eighth Embodiment

When a magnetoresistance effect film is mounted on a planar yoke head,if the distance between the magnetization free layer of themagnetoresistance effect film and yokes is shortened, the flow of amagnetic flux due to signal is smooth. If a vertically current applyingmagnetoresistance effect film is mounted, a bottom electrode is arrangedtherebetween, so that the distance between the magnetization free layerand the yokes is relatively long.

On the other hand, this embodiment relates to a design wherein thedistance between a magnetization free layer and yokes is decreased.

FIG. 20 is a schematic perspective view showing the construction of aprincipal part of a magnetic head in this embodiment. Also in thisfigure, the same reference numbers are given to the same element asthose described above referring to FIGS. 1 through 19 and 31 to omit thedetailed descriptions thereof.

If a bottom electrode 12 is arranged in a gap between yokes 20 and 20 asshown in this figure, the distance between a magnetoresistance effectfilm 13 and the yokes 20. Furthermore, a pair of biasing films of amagnetically hard film or an antiferromagnetic film for applying amagnetic field due to bias to the yokes 20 and the magnetization freelayer 13F in y direction are provided in the front and rear sides in thefigure although they are not shown in FIG. 20.

In the construction of FIG. 20, there is a problem in that the magneticfield due to current from a bottom electrode 12 is applied to themagnetoresistance effect film 13 and the yokes 20. For example, if asense current Is is caused to flow through a pillar electrode 14 in −zdirection, a magnetic field M due to current is generated in +xdirection.

On the other hand, if a top electrode 15 is arranged in parallel to thebottom electrode 12 as shown in the figure so that the sense currentgoes and returns, the magnetic field M due to current applied from thetop electrode 15 to the bottom electrode 12 can be substantiallyignored.

However, the magnetic field due to current applied to themagnetoresistance effect film 13 is further increased, so that themagnetization (arrows) rotates particularly in the central portion ofthe element to have an x component as shown in the magnetizationdistribution of FIG. 21. Since the magnetic permeability in a directionperpendicular to the direction B of magnetization in the biasing films30 is highest, the magnetic flux entering the yokes 20 on the straightin the track longitudinal direction (x direction) from a magneticrecording medium is bent in the magnetization free layer of themagnetoresistance effect film as shown by arrows in the figure. That is,the “skew” is caused in the magnetic flux F due to signal.

In view of this, if the shape of the horizontal cross section of thepillar electrode 14 is a parallelogram as shown in FIG. 21 and if thepillar electrode 14 is provided in a portion on which the magnetic fluxF due to signal from the track concentrates, the active region 13A ofthe magnetoresistance effect film can be set at a sensitive place, sothat it is possible to obtain a high output.

Specifically, when the direction of the magnetic field B due to bias is+y direction and the direction of the sense current Is is −z direction,the four vertexes of the parallelogram of the horizontal cross sectionof the pillar electrode 14 are designed so that B(a, −c), C(a, b) andD(0, b+c) assuming that A (0, 0) as shown in FIG. 22. That is, the shapeof a surface of the pillar electrode 14 contacting the magnetoresistanceeffect film has an edge portion which is inclined from a directionperpendicular to the magnetizing direction of the yokes 20 toward themagnetization rotating direction of the magnetization free layer of themagnetoresistance effect film (sides DC and AB in this example). Inaddition, the pillar electrode 14 is arranged so as to be shifted fromthe center of the magnetoresistance effect film 13 in −y direction.

MODIFIED EXAMPLE 8-1

It is more effective if the shape of the horizontal cross section of thepillar electrode 14 or the pillar intermediate non-magnetic layer 13S(see FIG. 5) is combined with the seventh embodiment so as to be a shapehaving both characteristics of a parallelogram and a trapezoid.

That is, when the direction of the magnetic field B due to bias is +ydirection and the direction of the sense current Is is −z direction, thefour vertexes may be designed so that B(a, −c), C(a, b) and D(0, d)(d>b+c) assuming that A (0, 0) as shown in FIG. 23. Also in this case,the shape of a surface of the pillar electrode 14 contacting themagnetoresistance effect film has an edge portion which is inclined froma direction perpendicular to the magnetizing direction of the yokes 20toward the magnetization rotating direction of the magnetization freelayer of the magnetoresistance effect film (sides DC and AB in thisexample). In addition, the shape of a surface of the pillar intermediatenom-magnetic layer 13S contacting the stacked film 13P or the stackedfilm 13F has an edge portion which is inclined from a directionperpendicular to the magnetizing direction of the yokes 20 toward themagnetization rotating direction of the magnetization free layer of themagnetoresistance effect film (sides DC and AB in this example).

MODIFIED EXAMPLE 8-2

The concept of this embodiment can be applied to the magnetoresistanceeffect film 13 wherein the intermediate non-magnetic layer 13S is formedso as to have a pillar shape as illustrated in FIG. 5. That is, if thepillar non-magnetic layer 13S is provided at a position as shown in FIG.22 or 23 so as to have a shape as shown therein, it is possible toobtain a high output.

Ninth Embodiment

When the bottom electrode is arranged in the gap between the yokes asthe above described eighth embodiment, if the top electrode is arrangedin parallel thereto and if the shape of the horizontal cross section ofthe pillar electrode is the shape shown in FIG. 22, it is possible toavoid the effects of the rotation of magnetization in the magnetizationfree layer, which is caused by the magnetic field due to current from aportion other than the pillar electrode.

On the other hand, in this embodiment, a construction for preventing therotation of magnetization caused by such a magnetic field due tocurrent.

FIG. 24 is a schematic perspective view showing the construction of aprincipal part of a magnetic head in this embodiment. Also in thisfigure, the same reference numbers are given to the same elements asthose described above referring to FIGS. 1 through 23 and 31 to omit thedetailed explanations thereof.

In this embodiment, as illustrated in FIG. 24, a bottom electrode 12 anda top electrode 15 are taken out in a longitudinal direction of arecording track 200T to cause a sense current Is to go and return. Thus,the direction of a magnetic field M due to current applied to amagnetization free layer 13F by the top electrode 15 and the bottomelectrode 12 can be the same as the direction of a magnetic field B dueto bias which is caused by a pair of biasing films (not shown).Specifically, if a sense current is applied to a pillar electrode 14 ina −z direction, the direction of the magnetic field M due to current is−y direction.

MODIFIED EXAMPLE 9-1

In fact, for example, a current distribution shown in FIG. 25 is formedin the top electrode 15 since the sense current Is concentrates on thepillar electrode 14. In this case, a current distribution in theopposite direction thereto is formed in the bottom electrode 12. Then,an annular magnetic field M due to current shown in FIG. 25 is generatedin the magnetoresistance effect film 13.

In order to avoid this, the top electrode 15 and the bottom electrode 12are provided current constriction regions 15 a and 12 a, respectively,as illustrated in FIG. 26. These current constriction regions have ashape which is narrowed in the vicinity of the pillar electrode 14.Thus, as shown in FIG. 27, the current distribution does not concentratein the vicinity of the pillar electrode 14. For example, if a current isapplied to the pillar electrode 14 in −z direction, the direction of themagnetic field due to current applied to the magnetoresistance effectfilm 13 can be generally −y direction as shown in FIG. 27. Furthermore,only one of the top electrode 15 and the bottom electrode 12 may beprovided with the current constriction region.

Tenth Embodiment

As the tenth embodiment of the present invention, a magnetic readingsystem according to the present invention will be described below. Themagnetoresistance effect elements or the magnetic heads according to thefirst through the ninth embodiments of the present invention can beincorporated in, e.g., a recording/reproducing integral magnetic headassembly, to be mounted in a magnetic reproducing system.

FIG. 28 is a perspective view of a principal part showing an example ofa schematic construction of such a magnetic recording system. That is, amagnetic recording and/or reproducing system 150 according to tenthembodiment of the present invention is a system of a type in which arotary actuator is used. In this figure, a longitudinal recording orvertical recording magnetic disk 200 is mounted on a spindle 152, and isrotated in a direction of arrow A by means of a motor (not shown) whichis driven in response to a control signal from a drive unit control part(not shown). The magnetic disk 200 has a longitudinal recording orvertical recording layer. A head slider 153 for recording/readinginformation in the magnetic disk 200 is mounted on the tip of athin-film-like suspension 154. The head slider 153 has a magnetic head,which uses a magnetoresistance effect element in any one of the abovedescribed embodiment, in the vicinity of the tip thereof.

If the magnetic disk 200 rotates, the medium facing surface (ABS) of thehead slider 153 is held so as to be spaced from the surface of themagnetic disk 200 by a predetermined flying height.

The suspension 154 is connected to one end of an actuator arm 155 whichhas a bobbin portion for holding a driving coil (not shown). On theother end of the actuator arm 155, there is provided a voice coil motor156 which is a kind of linear motor. The voice coil motor 156 comprisesa driving coil (not shown) wound onto the bobbin portion of the actuatorarm 155, and a magnetic circuit comprising a permanent magnet and afacing yoke which face each other so as to sandwich the coiltherebetween.

The actuator arm 155 is held by ball bearings (not shown) which areprovided at two places above and below a fixed axis 157, and isrotatable and slidable by the voice coil motor 156.

FIG. 29 is an enlarged perspective view of a magnetic head assembly infront of the actuator arm 155 viewed from the side of a disk. That is, amagnetic head assembly 160 has an actuator arm 151 having, e.g., abobbin portion for holding a driving coil, and a suspension 154 isconnected to one end of the actuator arm 155.

On the tip of the suspension 154, a head slider 153 having a readingmagnetic head using any one of the above described magnetoresistanceeffect elements referring to the first embodiment through the ninthembodiment is mounted. A recording head may be combined therewith. Thesuspension 154 has a lead wire 164 for writing/reading signals. Thislead wire 164 is electrically connected to the respective electrodes ofthe magnetic head incorporated in the head slider 153. In the figure,reference number 165 denotes an electrode pad of the magnetic headassembly 160.

Between the medium facing surface (ABS) of the head slider 153 and thesurface of the magnetic disk 200, a predetermined flying height is set.

FIG. 30(a) is a conceptual drawing showing the relationship between thehead slider 153 and the magnetic disk 200 when the flying height is apredetermined positive value. As illustrated in this figure, in usualmany magnetic recording systems, the slider 153 including the magnetichead 10 operates while flying at a predetermined height from the surfaceof the magnetic disk 200. According to the tenth embodiment of thepresent invention, such a “flying traveling type” magnetic recordingsystem can also read at low noises with a higher resolution thanconventional systems. That is, by adopting any one of the abovedescribed magnetoresistance effect elements referring to the firstembodiment through the ninth embodiment, weak magnetization informationfrom a track to be read can be surely read. That is, since it ispossible to reduce the cross talk from adjacent recording track, it ispossible to reduce the track pitch to greatly improve the recordingdensity.

On the other hand, if the recording density further increases, it isrequired to lower the flying height to glide the slider nearer to themagnetic disk 200 to read information. For example, in order to obtain arecording density of about 40 G (giga) bits per one square inch, thespacing loss due to the flying of the slider is too large, so that it isnot possible to ignore the problem of the collision of the head 10 withthe magnetic disk 200 due to the very low flying.

For that reason, a system for traveling the slider while positivelycausing the magnetic head 10 to contact the magnetic disk 200 is alsoconsidered.

FIG. 30(b) is a conceptual drawing showing the relationship between sucha “contact traveling type” head slider 153 and the magnetic disk 200.The magnetic head according to the present invention can also be mountedon the “contact traveling type” slider by providing a diamond-likecarbon (DLC) lubricating film on the contact surface to the medium.Therefore, the “contact traveling type” magnetic reading systemillustrated in FIG. 24(b) can also greatly reduce crosstalk fromadjacent tracks to greatly reduce the track pitch in comparison withconventional systems to stably carry out a recording/reading operationin a medium having a higher density.

As described above, referring to the accompanying drawings, the presentinvention has been described. However, the present invention should notbe limited to those described in the respective examples.

For example, the material and the shape of elements of the magnetic headshould not be limited to those described in the respective examples, andthe present invention can include all embodiments, which can be selectedby persons with ordinary skill, to provide the same effects.

The magnetic reproducing system may be a reproducing only system or arecording and/or reproducing system. In addition, the medium should notbe limited to a hard disk, but it may be any one of all magneticrecording media, such as flexible disks and magnetic cards. Moreover,the magnetic reproducing system may be a so-called “removable” typesystem wherein a magnetic recording medium is removed from the system.

As described above, according to the present invention, it is possibleto to provide a magnetoresistance effect element capable of preciselydefining the active region of an MR film in a CPP type MR element and ofeffectively suppressing the influence of a magnetic field due to currentfrom an electrode, and a magnetic head and magnetic reproducing systemusing the same. Therefore, it is of great advantage to industry.

While the present invention has been disclosed in terms of theembodiment in order to facilitate better understanding thereof, itshould be appreciated that the invention can be embodied in various wayswithout departing from the principle of the invention. Therefore, theinvention should be understood to include all possible embodiments andmodification to the shown embodiments which can be embodied withoutdeparting from the principle of the invention as set forth in theappended claims.

1-7. (canceled)
 8. A magnetoresistance effect element comprising: astacked film including a magnetization fixed layer in which thedirection of magnetization is substantially fixed to one direction, anda magnetization free layer in which the direction of magnetizationvaries in response to an external magnetic field; an electrode connectedto a part of a principal plane of the stacked film; themagnetoresistance effect element having a resistance varying in responseto a relative angle between the direction of magnetization in themagnetization fixed layer and the direction of magnetization in themagnetization free layer; a sense current detecting the variation of theresistance being applied to the film planes of the magnetization fixedlayer and the magnetization free layer via the electrode in a directionsubstantially perpendicular to the magnetization fixed layer and themagnetization free layer; the electrode comprising a pillar electrodeportion substantially perpendicularly extending from the principal planeof the stacked film, and a feed portion extending substantially inparallel to the principal plane of the stacked film; and the pillarelectrode portion having two conductive layers in the central portionand outer peripheral portion thereof, and the sense current being causedto flow in the opposite directions to each other in the central portionand the outer peripheral portion.
 9. A magnetoresistance effect elementcomprising: a stacked film including a magnetization fixed layer inwhich the direction of magnetization is substantially fixed to onedirection, and a magnetization free layer in which the direction ofmagnetization varies in response to an external magnetic field; anelectrode connected to a part of a principal plane of the stacked film;the magnetoresistance effect element having a resistance varying inresponse to a relative angle between the direction of magnetization inthe magnetization fixed layer and the direction of magnetization in themagnetization free layer; a sense current detecting the variation of theresistance being applied to the film planes of the magnetization fixedlayer and the magnetization free layer via the electrode in a directionsubstantially perpendicular to the magnetization fixed layer and themagnetization free layer; the electrode comprising a pillar electrodeportion substantially perpendicularly extending from the principal planeof the stacked film, and a feed portion extending substantially inparallel to the principal plane of the stacked film; and themagnetoresistance effect element further comprising a magnetic shieldprovided around the pillar electrode portion.
 10. A magnetic headcomprising: a pair of yokes arranged so as to face each other via amagnetic gap; a magnetoresistance effect element magnetically coupled tothe pair of yokes; the pair of yokes having a magnetization arranged ina predetermined direction; the magnetoresistance effect elementcomprising, a stacked film including a magnetization fixed layer inwhich the direction of magnetization is substantially fixed to onedirection, and a magnetization free layer in which the direction ofmagnetization varies in response to an external magnetic field, and anelectrode connected to a part of a principal plane of the stacked film;the magnetoresistance effect element having a resistance varying inresponse to a relative angle between the direction of magnetization inthe magnetization fixed layer and the direction of magnetization in themagnetization free layer; a sense current detecting the variation of theresistance being applied to the film planes of the magnetization fixedlayer and the magnetization free layer via the electrode in a directionsubstantially perpendicular to the magnetization fixed layer and themagnetization free layer; and the shape of a connecting portion forconnecting the principal plane to the electrode having an edge portioninclined in a magnetization rotating direction of the magnetization freelayer from a direction perpendicular to the magnetizing direction of theyokes.
 11. A magnetic head as set forth in claim 10, wherein the shapeof the connecting portion for connecting the principal plane to theelectrode is asymmetric with respect to the center of the connectingportion.
 12. A magnetic head as set forth in claim 11, wherein the shapeof the connecting portion for connecting the principal plane to theelectrode is substantially a quadrilateral.
 13. A magnetic headcomprising: a pair of yokes arranged so as to face each other via amagnetic gap; a magnetoresistance effect element magnetically coupled tothe pair of yokes; the pair of yokes having magnetization arranged in apredetermined direction; the magnetoresistance effect elementcomprising, a first stacked film including a magnetization fixed layerin which the direction of magnetization is substantially fixed to onedirection, a second stacked film including a magnetization free layer inwhich the direction of magnetization varies in response to an externalmagnetic field, and a non-magnetic intermediate layer provided betweenthe first stacked layer and the second stacked layer; themagnetoresistance effect element having a resistance varying in responseto a relative angle between the direction of magnetization in themagnetization fixed layer and the direction of magnetization in themagnetization free layer; the area of a contact portion of a principalplane of the first stacked film contacting the non-magnetic intermediatelayer being smaller than the area of the principal plane of the firststacked film; the area of a contact portion of a principal plane of thesecond stacked film contacting the non-magnetic intermediate layer beingsmaller than the area of the principal plane of the second stacked film;a sense current detecting the variation of the resistance being appliedto the film planes of the magnetization fixed layer, the non-magneticintermediate layer and the magnetization free layer in a directionsubstantially perpendicular thereto; and the shape of a connectingportion for connecting the non-magnetic intermediate layer to theprincipal plane of the first stacked film having an edge portioninclined in a magnetization rotating direction of the magnetization freelayer from a direction perpendicular to the magnetizing direction of theyokes.
 14. A magnetic head comprising: a pair of yokes arranged so as toface each other via a magnetic gap; a magnetoresistance effect elementprovided on the pair of yokes and magnetically coupled to the pair ofyokes; the pair of yokes having magnetization arranged in apredetermined direction; the magnetoresistance effect elementcomprising, a stacked film including a magnetization fixed layer inwhich the direction of magnetization is substantially fixed to onedirection, and a magnetization free layer in which the direction ofmagnetization varies in response to an external magnetic field, a topelectrode connected to a part of an upper principal plane of the stackedfilm, and a bottom electrode connected to a lower principal plane of thestacked film; the magnetoresistance effect element having a resistancevarying in response to a relative angle between the direction ofmagnetization in the magnetization fixed layer and the direction ofmagnetization in the magnetization free layer; a sense current detectingthe variation of the resistance being applied to the film planes of themagnetization fixed layer and the magnetization free layer via theelectrode in a direction substantially perpendicular to themagnetization fixed layer and the magnetization free layer; the topelectrode having a pillar electrode portion substantiallyperpendicularly extending from the principal plane of the stacked film,and a feed portion extending substantially in parallel to the principalplane of the stacked film; the bottom electrode extending in a directionperpendicular to the direction of magnetization of the yokes; and thefeed portion of the top electrode being provided so that the sensecurrent flowing through the feed portion is anti-parallel to a sensecurrent flowing through the bottom electrode.
 15. A magnetic head as setforth in claim 14, wherein at least one of the top electrode and thebottom electrode has a current constriction region at a position of agap between the pair of yokes, the area of the current constrictionregion being wider than a region of the pillar electrode contacting thestacked layer. 16-20. (canceled)
 21. A magnetic head comprising: a pairof yokes arranged in parallel with each other in a first direction; amagnetoresistance element magnetically coupled to the pair of yokes;each yoke of the pair of yokes having a magnetization in a seconddirection that is substantially perpendicular to the first direction;the magnetoresistance element including, a stacked film having amagnetization fixed layer in which a direction of magnetization issubstantially fixed to one direction, and a magnetization free layer inwhich a direction of magnetization varies in accordance with an externalmagnetic field, and an electrode connected to a part of a principalplane of the stacked film; the magnetoresistance element having aresistance varying in response to a relative angle between the directionof magnetization in the magnetization fixed layer and the direction ofmagnetization in the magnetization free layer; a sense current detectinga variation of the resistance flowing via the electrode in asubstantially perpendicular direction relative to layer surfaces of themagnetization fixed layer and the magnetization free layer; when thefirst direction is an X axis direction, the second direction is a Y axisdirection, and a direction perpendicular to a film surface of thestacked film is a Z axis direction, a direction of magnetization of theyokes is along a positive Y axis direction, a direction in which thesense current flows is along a negative Z axis direction, and adirection in which a right-hand screw proceeds when the Y axis isrotated so that the positive Y axis direction overlaps the positive Zaxis direction is a positive X axis direction; a shape of a connectionpart connecting the principal plane and the electrode being a rectanglehaving a first side which is in parallel with to Y axis direction, asecond side which is parallel to the Y axis direction, located at apositive side of the X axis direction relative to the first side, andlonger than the first side, a third side making an acute angle with oneof the first side and the second side, and making an obtuse angle withanother of the first side and the second side, and a fourth side makingan acute angle with one of the first side and the second side, andmaking an obtuse angle with another of the first side and the secondside; and the connection part being arranged so that a magnetic fluxentering from an adjacent track lessens.
 22. A magnetic head comprising:a pair of yokes arranged in parallel with each other in a firstdirection; a magnetoresistance element magnetically coupled to the pairof yokes; each yoke of the pair of yokes including a magnetization in asecond direction which is substantially perpendicular to the firstdirection; the magnetoresistance element including, a first stacked filmincluding a magnetization fixed layer in which a direction ofmagnetization is fixed substantially in one direction, a second stackedfilm including a magnetization free layer in which a direction ofmagnetization varies in accordance with an external magnetic field, anda nonmagnetic intermediate layer formed between the first stacked filmand the second stacked film; the magnetoresistance element having aresistance varying in response to a relative angle between the directionof magnetization in the magnetization fixed layer and the direction ofmagnetization in the magnetization free layer; an area of a contact partbetween a principal plane of the first stacked film and the nonmagneticintermediate layer being smaller than an area of the principal plane ofthe first stacked film; an area of a contact part between a principalplane of the second stacked film and the nonmagnetic intermediate layerbeing smaller than an area of the principal plane of the second stackedfilm; a sense current detecting a variation of the resistance flowing ina substantially perpendicular direction relative to layer surfaces ofthe magnetization fixed layer, the nonmagnetic intermediate layer, andthe magnetization free layer; when the first direction is an X axisdirection, the second direction is a Y axis direction, and a directionperpendicular to a film surface of the stacked films to be a Z axisdirection, a direction of magnetization of the yokes is along a positiveY axis direction, a direction in which the sense current flows is alonga negative Z axis direction, and a direction in which a right-hand screwproceeds when the Y axis is rotated so that the positive Y axisdirection overlaps the positive Z axis direction is a positive X axisdirection; a shape of a connection part connecting the nonmagneticintermediate layer and the principal plane of the first stacked filmbeing a rectangle having a first side which is parallel with the Y axisdirection, a second side which is parallel to the Y axis direction,located at a positive side of the X axis direction relative to the firstside, and longer than the first side, a third side making an acute anglewith one of the first side and the second side, and making an obtuseangle with another of the first side and the second side, and a fourthside making an acute angle with one of the first side and the secondside, and making an obtuse angle with another of the first side and thesecond side, the connection part connecting the nonmagnetic intermediatelayer and the principal plane of the first stacked film being arrangedso that a magnetic flux entering from an adjacent track lessens; and ashape of a connection part connecting the nonmagnetic intermediate layerand the principal plane of the second stacked film being a rectanglehaving a fifth side which is in parallel with the Y axis direction, asixth side which is in parallel with the Y axis direction, located at apositive side of the X axis direction relative to the fifth side, andlonger than the fifth side, a seventh side making an acute angle withone of the fifth side and the sixth side, and making an obtuse anglewith another of the fifth side and the sixth side, and an eighth sidemaking an acute angle with one of the fifth side and the sixth side, andmaking an obtuse angle with another of the fifth side and the sixthside, the connection part connecting the nonmagnetic intermediate layerand the principal plane of the second stacked film being arranged sothat a magnetic flux entering from an adjacent track lessens.
 23. Amagnetic head as set forth in claim 21, wherein the connection part ispositioned so as to decrease an influence of a magnetic flux from anadjacent side track.
 24. A magnetic head as set forth in claim 22,wherein the connection parts are positioned so as to decrease aninfluence of a magnetic flux from an adjacent side track.
 25. A magnetichead comprising a magnetoresistance effect element as set forth in claim8.
 26. A magnetic head comprising a magnetoresistance effect element asasset forth in claim
 9. 27. A magnetic reproducing system comprising amagnetic head as set forth in claim 21 configured to read magneticinformation stored in a magnetic recording medium.
 28. A magneticreproducing system comprising a magnetic head as set forth in claim 22configured to read magnetic information stored in a magnetic recordingmedium.
 29. A magnetic reproducing system comprising a magnetic head asset forth in claim 10 configured to read magnetic information stored ina magnetic recording medium.
 30. A magnetic reproducing systemcomprising a magnetic head as set forth in claim 13 configured to readmagnetic information stored in a magnetic recording medium.
 31. Amagnetic reproducing system comprising a magnetic head as set forth inclaim 14 configured to read magnetic information stored in a magneticrecording medium.